QQmlImageProviderBase Class

QQmlImageProviderBase class is used to register image providers in the QML engine. 更多...

头：	#include <QQmlImageProviderBase>
qmake:	QT += qml
继承者：	QQuickImageProvider

所有成员列表，包括继承成员

公共类型

enum	Flag { ForceAsynchronousImageLoading }
flags	Flags
enum	ImageType { Image, Pixmap, Texture, ImageResponse }

公共函数

virtual Flags	flags () const = 0
virtual ImageType	imageType () const = 0

详细描述

QQmlImageProviderBase class is used to register image providers in the QML engine.

Image providers must be registered with the QML engine. The only information the QML engine knows about image providers is the type of image data they provide. To use an image provider to acquire image data, you must cast the QQmlImageProviderBase pointer to a QQuickImageProvider 指针。

另请参阅 QQuickImageProvider and QQuickTextureFactory .

成员类型文档编制

enum QQmlImageProviderBase:: Flag
flags QQmlImageProviderBase:: Flags

Defines specific requirements or features of this image provider.

常量	值	描述
`QQmlImageProviderBase::ForceAsynchronousImageLoading`	`0x01`	Ensures that image requests to the provider are run in a separate thread, which allows the provider to spend as much time as needed on producing the image without blocking the main thread.

Flags 类型是 typedef 对于 QFlags <Flag>。它存储 Flag 值的 OR 组合。

enum QQmlImageProviderBase:: ImageType

Defines the type of image supported by this image provider.

常量	值	描述
`QQmlImageProviderBase::Image`	`0`	The Image Provider provides QImage images. The QQuickImageProvider::requestImage () method will be called for all image requests.
`QQmlImageProviderBase::Pixmap`	`1`	The Image Provider provides QPixmap images. The QQuickImageProvider::requestPixmap () method will be called for all image requests.
`QQmlImageProviderBase::Texture`	`2`	The Image Provider provides QSGTextureProvider based images. The QQuickImageProvider::requestTexture () method will be called for all image requests.
`QQmlImageProviderBase::ImageResponse`	`4`	The Image provider provides QQuickTextureFactory based images. Should only be used in QQuickAsyncImageProvider or its subclasses. The QQuickAsyncImageProvider::requestImageResponse () method will be called for all image requests. Since Qt 5.6

成员函数文档编制

`[pure virtual]` Flags QQmlImageProviderBase:: flags () const

Implement this to return the properties of this image provider.

`[pure virtual]` ImageType QQmlImageProviderBase:: imageType () const

Implement this method to return the image type supported by this image provider.

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